In politics, there are no perfect answers. It is a question of compromise, and plotting the what seems to be the best path towards ideals from the numerous paths available.
While the "libertarian" argument against BI seems to consist of mostly taxes are theft (unless they support things I support) and an over-reliance on the government, which leads to increased government power.
For BI, if everyone is essentially getting the same, that reduces government power, as they lose the authority to pick winners and losers from the public trust. Can't pander to certain groups for increased benefits (such is commonly done with the elderly). Can't promise any increases unless it goes to everyone. That is a very libertarian argument at reducing the influence of government (plus getting rid of entire agencies that oversee the various programs. You've just reduced the size of government tremendously).
With regards to taxation, while overall taxes will probably increase, since the bulk of taxes goes directly to the population, that leaves little room for government largesse in terms of subsidies, pet programs, and other attempts to curry favor. The money simply isn't there.
I invite libertarians to look carefully at cost/benefit of BI in terms of overall goals, and especially means to achieve those goals through other means (it's not like libertarianism has caught fire with the public at large). If there is a better way forward, I'd certainly like to hear it.