I don't understand your phraseology "more difficult". Are you referring to competitiveness of the two audition pools, academic criteria, strength of program?
The UCLA program is a BA rather than a BM track (although a BA in music is available at UT Austin), and as such has less music/performance and more liberal arts in the degree requirements.
Compare the audition requirements (or suggested audition rep) at the two programs. Most audition based BA programs audition requirements are 'lighter" than what one might expect from a BM program.
Some past comments on UT Austin, and Brian Lewis in particular in the links below. Sandy Yamamota and Dan Ching, both of the Miro quartet round out the violin faculty at Butler.
Money problems $$ Wonderful News for UT Austin