Sentence structure difference:
The first sentence is ‘subject + be + always + verb-ing,’
Without the active verb, ”be”, the sentence is simply a habitual aspect to state the habit, which time is unspecified.
The second sentence is ‘subject + always + verb’ is the pattern of the second sentence.
With the progressive auxiliary ‘be,’ the sentence becomes habitual present progressive. The action referred to is likely to be an ongoing event, or the event might be taking place right at speech time in the first sentence.
Another potential explanation: The event is always happening right now and is an obvious exaggeration, but it might very simply explain the reason the statements are frequently perceived as being over-subjective and serve to convey the perspective of the speaker on the incident. In other words, the context of the sentence with a progressive aspect marker places particular emphasis on intensifying the tone. The speaker may be annoyed by the habit of the actor, and adding ‘be’ allows the speaker to express the unsatisfactory and highlight the constant frequency of the event.