The problem in this case is that a single veto stops everything. To get anything throu the EU it has to be a compromise. That is just the nature of a multi state system, with even more parties. So usually those laws are not that insane, as the commone ground is generally speaking in the political center. The veto rule gives extremist minorities a lot more power, as 26 of the members can agree, but one can stop it. So if you are not a political radical in the EU political landscape, this rule is good for you.
However members bailing is possible, but it is balanced out with greater unity allowing for economy of scale in a lot of fields. So loosing a few members might very well be worth it for the EU, if it turns the EU into a proper country.