There are worse lenses to be "stuck" with than the Pentax limiteds (31, 43, and 77), the DFA 100 macro is excellent, the 70-200 is reported to be excellent as well, and the DA* primes are full-frame compatible. I don't think there's been bad reviews of the 2 rebadged Tamron lenses either (15-30 and 24-70 2.8s, but now with Pentax coatings and WR).
Who needs plenty of options when the options we have are good to great and not overly expensive?