Some attorneys mess up deals. Really. Sometimes it is in the client's best interest to mess up the deal. ie there is a lot of risk, and this needs to be examined carefully. Sometimes, it is simply a risk averse attorney who wants to make you aware of risks that are not terribly relevant to you. Some attorneys are so late getting back to you, that you miss your deadline for contract review and that messes up the deal.
Now, a realtor is not going to recommend an attorney known for messing up deals. It's as simple as that.
If your agent has recommended an attorney, the attorney will probably respond a bit quicker because they have worked together before. You might actually get better service because again, they have worked with your realtor before. They might mutually refer business to each other. It doesn't make one or the other bad, Probably makes them both pretty good or they would not send referrals.
The realtors here have given you very good advice: Make sure the attorney is someone who specializes in real estate. In a city, that may be all they do. In a small town, they cannot rely on real estate alone but it should still be a significant part of their practice. You woudn't let your dentist practice surgery on you.
If this is a pure vanilla transaction, you are probably OK, maybe better off with their recommendation. The realtor is also sensitve to the fees that are charged and most will not use an attorney whose fees are out of line.
Here's my cautionary tale: many years ago, I bought an out of state vacation home. I asked my realtor to recommend a home inspector. She strongly discouraged me, stating "It's not customary to do home inspections here." I insisted and used the inspector she recommended. Some how he failed to turn on the water in the finished lower level, which would have revealed the numerous defects that the home had. The attorney, also recommended by the realtor, told me that there was nothing that I could do about it.
I think those instances are the exception, not the rule, but I do a lot of due diligence now before hiring any professional.