i don't see any reason other than it can be very expensive through them. you can also go to your local feed stores or green houses if they are open during the late winter or early spring. they may have other brands and neat varieties that Ferry Morse may not provide to the store. i do know that those displays they ship to the stores usually have seed varieties that may not do so well in an area and better for other areas of the country.
i used to get my seeds in January from the local drug store or the dollar store when they would get the American Seed or equivalent sounding brand they used to sell for 10 cents a pack. now they sell for about 20 cents a pack. Wal-mart also carries that brand in our area along with Burpee (which i don't like to buy anymore). i have bought through catalogs for seeds i can't find in our area anymore or that were developed for our climate and just don't easily find on the shelves here.
If you live in a rural community, an independant garden/farm store may carry bulk seed they pack themselves. It is usually a lot cheaper than pre-packaged seed, and/or you get a lot more seed per pack. Sometimes they do carry varieties you can't find prepackaged. You can ask them what the popular varieties are. There are reasons they are popular--they do well locally.
If you are wanting rarer varieties, you can shop online at many different seed sellers. Spend an evening searching the web for --say--heirloom bean seed, for example. You will find large and small businesses, and lots of variety, and lots of different prices.
Every company that sells seed is required to test the germination every year, and have it available for you, if not posted on the package. Most of the time when the seed you plant does not come up, it is not the germination at fault. Ground temperature and moisture are the big issues. There are governmental guidelines that dictate what is acceptable germination rates for various seeds, to still be sellable. This being said, I would not buy seed that has been kept in a hot greenhouse display rack over the summer, as heat affects the germination rate, and that particular pack of seed may no longer be good.
I think Lowes would be OK. But don't you think buying locally is much more beneficial to your area? Yup, most local mom-n-pop garden shops are a little more expensive but driving 10 miles each way to the big box store to save $1.65 does not make sense.
I'm kind of in a rut now that I've learned who has what, but my first stop is the local gardening store, owned and operated by someone who lives here sprouts her own stuff in her greenhouse, tomatoes, peppers, and stuff like that. She's also got her suppliers, mostly pretty local, for some of the stuff. A couple of times when I've been in asking for stuff, Carla gets on the phone to find out when it will be in. She supplies a lot of local farmers and people that do the roadside stands as well as hobby gardeners like me. If I can get the seeds or started plants through her, I do. I find her prices reasonable for most things. Seed potatoes for instance. Try getting them shipped in for $0.45 per pound and pick the ones you want.
I also look for local plant sales, such as the Horticultural Club at the nearby University. There is one guy that sells "heritage" type plants outside the Natural Food store. And you can check some nurseries for maybe some started plants. But local is my first choice if I can at all.
My next stop is through the internet. This is for things I cannot get local. For example, Burpee has a couple of hybrid tomatoes that I can't get anywhere else that I like. I've ordered hops and stuff like that.
My last choice is the big box stores. You can sometimes get certain seeds through them for a lot less than paying shipping. For example, Lowe's carries some of the Burpee seeds I use. Some but not all. And occasionally I'll do impulse buys there. Just something I haven't tried and its cheaper than paying shipping. Not all things grow well here. I like to try them sometimes without spending a lot on shipping.
I try to buy local when I am buying plants... places like Lowes and wal mart have their plants shipped in from where ever and their employees havent a clue on how to take care of them... I like to buy seeds from catalogs my favs are Johnny's seeds in Maine, Baker Creek heirloom or Comstock Seed as they have seeds for my growing zone 4...if you live in the south it is best to buy seeds that grow best in the south...
I buy at my local feed store - they sell seeds that do well in the south and they are a local family owned business. I do buy seeds from Baker Creek and Tomato Fest also.
I used to be a seed snob and only bought from the big companies. However, in recent years any company seems able to produce seed that germinates. If you want more exotic varieties you will need to browse the seed catalogs. Many offer $25 off of $50 several times a year. If you buy near the end of the season for a second crop perhaps, you may find the way the stores have kept them have reduced their germination rate. One thing about the big seed companies, if you get a bad pack of seed they will refund your money or give you a credit.
Native Seed Search online is really great! Check out their Beans! Oh, and if you ever expect drought, Tepary Beans for dry soup beans are tough for droughts. A bit of sipping water and they are fine. Way more protein than common beans, great in Chili.