William--I have never had a problem with any parent not allowing their adult children to make their decision. I welcome parents comments in all circumstances and would much rather they spoke up before the negotiations and contract than waiting until futher into the deal to voice their concerns.
Teri it makes plain good sense to have parents involved in 1s timers home purchase. We almost always do, if they live close. And most 1st timers want their help!
Anna--Absolutely! They offer great advice and again, I would much rather address their concerns before the offer is placed rather than after the inspection contingency is removed. 
I feel the same way Teri! I think we parents have a lot of experience to share with our kids when they buy a home and not just becasue we are Realtors!
Barb--Some of my favorite deals have been where the parents were involved. It is a big decision and when a parent is there to guide & share concerns/experiences the buyer has a better chance of being a successful homeowner. Involved parenting doesn't end but it does change to more of an advisor role. :)
Some guidance from parents isn't always a bad thing as long as the parent gives the advice and then stays quiet letting the children make a decision.