United Airlines Inc.’s UAL, -0.23% CEO-designate, Scott Kirby, is one of the most recognizable airline executives in the U.S. after stints at America West, US Airways and American Airlines, but he is also a “somewhat polarizing figure,” Vertical Research Partners said Thursday. United announced earlier than CEO Oscar Munoz would move to the role of executive chairman in May, and that Kirby would replace him. “Bulls will argue that he is exceptionally-qualified, perhaps the best in the business, and that this transition should be orderly and mostly unnoticeable to us as he has led or at least played an integral role in all of the major decisions that have taken place at UAL over the last three years,” Vertical analyst Darryl Genovesi wrote in a note. “Bears, meanwhile, will argue that Mr. Kirby “needs a boss” as his aggressive competitive posture could lead to excess capacity and strategic pricing practices that some investors view as irrational.” Genovesi’s view is that Kirby’s decisions accept the need for short-term pain to achieve a long-term gain in a highly competitive industry. His critics “appear to consist primarily of those who fancy (or once fancied) the industry as ~oligopolistic post the 2008-13 consolidation wave, a thesis that, to us, now seems to have completely broken down.” In the last five years, Kirby’s push to match or undercut low-cost carriers has driven big revenue swings and capacity growth and United’s stock took a dive before a sharp recovery. The stock has actually doubled since his arrival at the airline in 2016, outperforming the broader industry by 75% as measured by the NYSE Arca Airline ETF XAL, +0.48%. United shares were down 0.1%, but have gained 28% in 2019, while the ETF has gained 19% and the S&P 500 SPX, -0.06% has gained 24%.