There are three possible reasons why you can be tempted by iNMR.
First reason: it's for research. It happens that they are not using iNMR in the industry, not because they don't like it, but because they don't buy Macs anymore in the industry. So, the majority of iNMR users are not doing repetitive activities. They don't ask to process 20 spectra in 20 seconds. Maybe they want to estimate the concentrations by time-consuming line-fitting or they want to monitor the phosphorylation of a protein by a series of thirty H-N HSQC, or they want to simulate the effect of a slow rotation, as they used to do with DNMR in the '70s. iNMR users asked for such things years ago and now you find them already into the program.
Second reason: students learn the program by themselves. Nowadays few research groups are pure-NMR-groups. When a new PhD students joins the lab, he has many techniques to learn, not just NMR processing. Luckily, iNMR has many things in common with the other applications he daily works with on his/her Mac. iNMR also helps novices to understand NMR processing because spectra are clearly depicted at every stage. A lot of things become natural after the first day of use.
Third reason: today Mestrelab has started a promotional sale, a sort of end-of-the-year clearance.
You can buy a disposable license at €90 instead of €150. You can download and try the program before buying.